To examine the association of muscular strength, as measured by handgrip strength test (HGs), with the presence/absence of fibromyalgia (FM) and FM severity in men.A total of 20 men (age, (mean age±standard deviation) of 48.0±8.0 years) with FM and 60 healthy subjects (age, 49.5±7.3 years) participated in the study. The HGs was measured by a maximal isometric test using a dynamometer with adjustable grip in both hands, and the average score was used in the analysis. All FM patients completed the Spanish version of the Fibromyalgia Impact Questionnaire (FIQ). Patients were classified as having moderate FM if the FIQ was <70 and as having severe FM if the FIQ was ≥70.HGs was ~17% lower in FM patients compared to healthy men (p=0.005) and ~27% lower in men with severe FM compared to those with moderate FM (p=0.03). Age-adjusted logistic regression models showed that 1 kilogram increment in HGs was associated with an 8% reduced risk of having FM (OR=0.92, 95% CI: 0.86-0.97, p=0.002). In the FM group, 1 kilogram increment in HGs was associated with a 13% reduced risk for having severe FM (OR=0.87, 95% CI: 0.76-0.99, p=0.04). HGs was negatively associated with pain, fatigue, stiffness and with the total score from the FIQ (all p<0.05).HGs is reduced in male FM patients and is inversely related to FM severity and symptomatology. HGs testing could be used as a complementary tool in the assessment and monitoring of FM. Further research on male FM patients is needed to confirm or contrast these findings.